Total hip replacement with a collarless polished cemented anatomic stem: clinical and gait analysis results at ten years follow-up

Purpose

The aim of this study was to determine outcomes of total hip replacement (THR) with the Lemania cemented femoral stem.

Methods

A total of 78 THR patients were followed and compared to 17 “fit”, healthy, elderly and 72 “frail” elderly subjects without THR, using clinical outcome measures and a portable, in-field gait analysis device at five and ten years follow-up.

Results

Forty-one patients (53 %), mean age 83.4 years, available at ten years follow-up, reported very good to excellent satisfaction. Mean Harris Hip and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores were 81.2 and 10.5 points, respectively, with excellent radiological preservation of proximal femur bone stock. Spatial and temporal gait parameters were close to the fit group and better than the frail group.

Conclusions

Lemania THR demonstrated very good, stable clinical and radiological results at ten years in an older patient group, comparable to other cemented systems for primary THR. Gait analysis confirmed good walking performance in a real-life environment.     

Knee Implant Loosening Detection: A Vibration Analysis Investigation

Knee implant loosening is mainly caused by the weakness of the prosthesis-bone interface and is the main reason for surgical revisions. However, pre-operative diagnosis is difficult due to lack of accurate tests. In this study, we developed a vibration-based system to detect the loosening of the tibial implant of an instrumented knee prosthesis. The proposed system includes an instrumented vibrator for transcutaneous stimulation of the bone in a repeatable manner, and accelerometer sensors integrated into the implants to measure the propagated vibration. A coherence-based detection technique was proposed to distinguish the loosened implants from the secure ones. Fourteen ex vivo lower limbs were used, on which the knee prosthesis was implanted, and harmonic-forced vibration was applied on the tibia. The input–output coherence measure provided 92.26% accuracy, a high sensitivity (91.67%) and specificity (92.86%). This technique was benchmarked against power spectrum based analysis of the propagated vibration to the implant. In particular, loosening detection based on new peak appearance, peak shift, and peak flattening in power spectra showed inferior performance to the proposed coherence-based technique. As such, application of vibration on our instrumented knee prosthesis together with input–output coherence analysis enabled us to distinguish the secure from loose implants.     

Classification and characterization of postural transitions using instrumented shoes

The frequency and quality of sit-to-stand and stand-to-sit postural transitions decrease with age and are highly relevant for fall risk assessment. Accurate classification and characterization of these transitions in daily life of older adults are therefore needed. In this study, we propose to use instrumented shoes for postural transition classification as well as transition duration estimation from insole force signals. In the first part, data were collected with 10 older adults and 10 young participants performing transitions in the laboratory while wearing the instrumented shoes, without arm assistance. A wavelet approach was used to transform the insole force data, and candidate events were selected for transition duration estimation. Transition durations were then validated against a model based on force plate reference. Vertical force estimation was also compared to force plate measurement. In the second part, postural transitions were classified in daily life using the instrumented shoes and validated against a highly accurate wearable system. Transition duration was estimated with an error ranging from 10 to 20% while the error for vertical force estimation was 7%. Postural transition classification was achieved with excellent sensitivity and precision exceeding 90%. In conclusion, the instrumented shoes are suitable for classifying and characterizing postural transitions in daily life conditions of healthy older adults.

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Graphical abstract “Experimental setup showing instrumented shoes, reference force plate, as well as IMUs used for postural transition classification and duration estimation comparison”

     

Alteration in Matrix Metalloproteinases (MMPS) Activity in Fibroblast Cell Line by Dexamethasone: A Possible Mechanism in Corticosteroid-Induced Glaucoma

Corticosteroids are often used as anti-inflammatory agents in a variety of inflammatory diseases. It is well established that long-term administration of corticosteroids predisposed the patients to develop glaucoma. Although the exact pathophysiology of steroid-induced glaucoma is unknown, it is assumed that Matrix metalloproteinases (MMPs) have a role in its pathogenesis. To study and estimate the pathophysiological effects of MMPs in glaucoma, we established an in vitro cell culture model. We also employed a precise proliferation assay to analyze cytotoxic effect of dexamethasone. The influence of dexamethasone on MMPs production was investigated using an in vitro gelatin Zymography. Cytotoxcity analysis of Dexamethasone revealed no significant cell death in low concentration. However, it caused 50% and 70% cell death at 80 and 100 mg/mL respectively. It also revealed an inhibitory effect on MMPs by dexamethasone in a dose dependent fashion. It may be concluded that an alteration in the level of MMPs expression by dexamethasone interferes with ocular fluid drainage and may contribute to the pathogenesis of glaucoma.     

Trichophyton mentagrophytes and T interdigitale genotypes are associated with particular geographic areas and clinical manifestations

The fungi Trichophyton mentagrophytes and T interdigitale account for significant amount of dermatophytosis cases worldwide. These two dermatophytes form a species complex and have a number of ribosomal internal transcribed spacer (ITS) region genotypes, allowing simultaneous species identification and strain typing. Our aim was to describe the geographic distribution of T mentagrophytes/T interdigitale ITS region genotypes and find an association between the genotypes and clinical presentations of respective infections. We performed rDNA ITS region sequencing in 397 Iranian T mentagrophytes/T interdigitale isolates and analysed all available in GenBank entries with sequences of this kind. For the study, 515 clinical annotations were available. Statistical analysis was performed by chi‐squared test and Spearman rank correlation analysis. A total of 971 sequences belonged to genotypes with at least 10 geographic annotations and were classified on the basis of exclusive occurrence in a particular region or high relative contribution to a regional sample. We discerned Asian and Oceanian (“ KU496915 ” Type V, “ KT192500 ” Type VIII, “ KU315316 ”), European (“ FM986750 ” Type III, “ MF926358 ” Type III*, “ KT285210 ” Type VI) and cosmopolitan (“ FM986691 ” Type I, “ JX122216 ” Type II, “ KP132819 ” Type II* and “ AF170453 ” Type XXIV) genotypes. There was statistically significant difference in the ITS genotype distribution between different affected body sites. Trichophyton mentagrophytes “ KT192500 ” Type VIII correlated with tinea cruris, T mentagrophytes “ KU496915 ” Type V correlated with tinea corporis, T interdigitale “ JX122216 ” Type II correlated with tinea pedis and onychomycosis. Trichophyton mentagrophytes and T interdigitale genotypes can be associated with distinct geographic locations and particular clinical presentations.     

Evaluation of IOL power calculation with the Kane formula for pediatric cataract surgery

Graefe's Archive for Clinical and Experimental Ophthalmology - To assess the accuracy of the Kane formula for intraocular lens (IOL) power calculation in the pediatric population. The charts of...     

Molecular diagnosis of X-linked chronic granulomatous disease in Iran

Chronic granulomatous disease (CGD) is an inherited disorder of pathogen killing by phagocytic leukocytes caused by mutations in NADPH oxidase subunits. Patients with CGD have life-threatening bacterial and fungal infections. Children’s Medical Center at Tehran University is the referral center for immunodeficiency in Iran. During 2 years of study, 11 non-consanguineous families with clinically diagnosed CGD were referred to this center. In functional assays performed on neutrophils from affected children and their mothers; no activity or strongly decreased oxidase activity was detected in the patients’ cells. In oxidase tests that scored this activity on a per-cell basis, a mosaic pattern was detected in the neutrophils from all 11 mothers. Western blot analysis revealed an X91° phenotype in all patients. Mutation screening in the CYBB gene encoding gp91^phox by SSCP analysis followed by sequencing showed nine different mutations, including two novel mutations. The present survey is the first study aimed to analyze the clinical features and the molecular diagnosis of X-CGD in Iranian patients.